Autoformat docs.

Change-Id: Ibc270de8cd6d8535e20847098175d8a00c67abe9
diff --git a/docs/PreparingLinux.md b/docs/PreparingLinux.md
index 283b9ce..9654960 100644
--- a/docs/PreparingLinux.md
+++ b/docs/PreparingLinux.md
@@ -8,7 +8,7 @@
 The Linux kernel for the primary VM can be built using the following
 command-line:
 
-``` shell
+```shell
 git clone https://github.com/torvalds/linux.git
 cd linux
 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make defconfig
@@ -24,7 +24,7 @@
 the kernel module, replacing `<kernel-path>` with the path to the kernel checked
 out in the previous section:
 
-``` shell
+```shell
 cd hafnium/driver/linux/
 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- KERNEL_PATH=<kernel-path> make
 ```
@@ -38,7 +38,7 @@
 construct a file system for the Linux RAM disk with the BusyBox shell as the
 init process.
 
-``` shell
+```shell
 git clone git://busybox.net/busybox.git
 cd busybox
 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make defconfig
@@ -48,7 +48,7 @@
 At this point you should ensure that the option `Settings > Build static binary
 (no shared libs)` is selected. Then you can proceed with the following commands:
 
-``` shell
+```shell
 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make -j24
 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make install
 cd _install
@@ -71,13 +71,13 @@
 section. Assuming the BusyBox root directory is in the same parent directory as
 the Hafnium root directory:
 
-``` shell
+```shell
 cp ../../hafnium/driver/linux/hafnium.ko .
 ```
 
 Then run the following commands:
 
-``` shell
+```shell
 find . | cpio -o -H newc | gzip > ../initrd.img
 cd ..
 ```